Nozzles are commonly used in connection with a motive fluid, such as water, to convert the stream from the motive fluid source into a stream or fog pattern to directly fight a fire, cool adjacent structures, cool individuals in high heat situations, and for mitigation of released toxic vapors. At times this quenching stream of ejected fluid is water focused through a nozzle which merely converts a pressure head, from the motive fluid source, to a velocity head so as to eject the fluid a distance away from the operator. Often it is desirable to aspirate the motive fluid stream and/or mix chemicals with the stream to create a foam to further aid in quenching a fire or mitigating fume emissions.
In the petroleum, petro-chemical, shipping industry, and other refining and manufacturing operations, in particular, it is necessary to have fire fighting equipment on hand and ready for immediate use. For these toxic type fires and/or spills it is common to mix chemicals with a motive fluid such as water. The resulting mixture is then ejected to quench the fire and/or mitigate the emission of toxic vapors. It is common in these situations for the mixture to be ejected as a foam or other mixed agent.
One agent commonly used is formed by mixing AFFF and PURPLE K powder with water to combat special type hazards. These special type mixes are especially effective in containing the emission of toxic fumes and quenching fires. However, one of the problems in forming and ejecting these agents is that the chemicals and a motive fluid, such as water, must be mixed just prior to ejection from a nozzle before the mixture becomes too viscous to eject in an effective manner. Another problem with prior nozzles is that the chemicals are not thoroughly mixed with the motive fluid thereby decreasing the effectiveness of the resulting mixture. In addition, with many of these prior art nozzles dry or solid chemicals are mixed at the ejection point of the nozzle resulting in the drop out of much of the chemical added. Further, the prior art nozzles have a tendency to clog when solid chemicals or debris enter the eduction device.
It would be a benefit, therefore, to have a nozzle which is capable of educting more than one chemical and mixing the chemicals in the motive fluid stream. It would be a further benefit to have a self-educting nozzle which educts and mixes the chemicals upstream of the nozzle outlet thereby effecting better mixing, expansion and reduction of drop out of the chemicals. It would be a still further benefit to have a self-educting nozzle which has no internal small bore diameter eductors or support type obstacles and parts thereby reducing clogging of the nozzle and increasing the range and effectiveness of the ejected stream.